Martin Supp

1H-NMR studies at N-acetyl-D-neuraminic acid ketosides for the determination of the anomeric configuration II.

Abstract In D 2 O solution the 1 H-nmr signal of the equatorially orientated protons at C-3 of N-acetyl-D-neuraminic acid and its derivatives shows a quite characteristic dependence on the anomeric configurations: δ [H(3e)] = 2.72 ± 0.05; δ [H(3a)] = 2.32 ± 0.08.

1H-NMR-Spektroskopische untersuchungen zur mutarotation der N-acetyl-D-neuraminsäure-ph-abhängigkeit der mutarotationsgeschwindigkeit

Abstract The pD-dependence of the mutarotation of N-acetyl-D-neuraminic acid was studied by 1 H-nmr spectroscopy. The rate constant has a minimum at pD 5.4. At pD 1.3 and pD 11.7 the establishment of the equilibrium of mutarotation was found to be so fast, that it cannot be measured.

1H-NMR-untersuchungen an sialinsäuren markierung von N-acetyl-D-neuraminsäure mit deuterium☆

Abstract An efficient method for the deuteration of N-acetyl-D-neuraminic-acid (NeuAc) at C-3 is described. In alkaline D2O solution both protons of NeuAc (H3a and H3e) will be substituted by deuterium, whereby the substitution effect was found to be faster for H3a than for H3e. The rate of this exchange depends strongly on the pD value: the rate increases with increasing pD value. In acidic solution no effect could be observed. The process of H-D-exchange is reversible.